I bought a new EOS 50D me recently, until then, I was operating with an EOS 350D and a Sigma 500 (a cost of about 200 €) Lightning and was always pleased with the flash. However, in combination with the EOS 50D was a dysregulation of SIGMA flash, which could only be remedied by a lengthy service at SIGMA. Therefore, I decided to buy a new compatible Canon flash (original accessories). Meanwhile, I have tested this new flash of Canon in practice and realized that this flash is superior not only by the higher-quality processing, but also by the improved behavior (performance) the SIGMA flash a lot.
Hence my recommendation: If you want to take pleasure in taking pictures, even in low light conditions, then you should fall back at the very beginning on a good flash and not (about 50 Euros in my case) to buy for a few bucks a lower quality flash. The flash is really recommended by the excellent workmanship and very good performance.
